TrueCrypt is a software designed to protect your important data by encrypting it. It can also maintain an on-the-fly-encrypted volume (data storage device).

Files can be copied to and from a mounted TrueCrypt volume just like they are copied to/from any normal disk (for example, by simple drag-and-drop operations). Files are automatically being decrypted on-the-fly (in memory/RAM) while they are being read or copied from an encrypted TrueCrypt volume.

Similarly, files that are being written or copied to the TrueCrypt volume are automatically being encrypted on-the-fly (right before they are written to the disk) in RAM. Note that this does not mean that the whole file that is to be encrypted/decrypted must be stored in RAM before it can be encrypted/decrypted. There are no extra memory (RAM) requirements for TrueCrypt.

Main Features:

* Creates a virtual encrypted disk within a file and mounts it as a real disk.

* Encrypts an entire partition or storage device such as USB flash drive or hard drive.

* Encrypts a partition or drive where Windows is installed (pre-boot authentication).

* Encryption is automatic, real-time (on-the-fly) and transparent.

* Parallelization and pipelining allow data to be read and written as fast as if the drive was not encrypted.

* Provides plausible deniability, in case an adversary forces you to reveal the password: